According to the prior art, there are several commercial system for digital audio reproduction in digital networks. For example following products are available today. The Gibson MaGIC™ network Cobra Net™, EtherSound™, Livewire™, MADI™ and others describe systems by which audio data may be streamed to digital loudspeakers or sound reproduction systems. Basically the quality of the reproduction in these systems is very good for home use but for professional use the digital transfer technology causes some problems.
In accordance with the prior art the above problem has been solved by buffering the information into receivers and controlling the unloading of the information from the receivers.
In more detail, to synchronize clocks over Ethernet connections the exact travel time of network packets must be measured. This is difficult for two reasons. First, standard network socket API will introduce random latency between calling the user-mode send-function and the actual output of the packet depending on the status of the operating system. The same applies also to reception of packets, the time between reception of packet from the network and its indication to user-mode process listening to the UDP socket cannot be accurately determined.
Secondly, when packet travels through network it will go through one or more hubs, switches or routers. Each device may randomly delay packets depending on the load of network and state of the device. This introduces random latency in travel time that cannot be predicted. When measured, it is found that the latency is nearly constant for most of the packets but some packets may be delayed by several hundreds of microseconds or even more.